Conventionally, an inkjet printer that includes an inkjet head in which a plurality of nozzles for discharging ink droplets onto a print medium is known (see JP 2012-51160 A).
As ink used by an inkjet printer, there are ones with too much viscosity at normal temperature to be discharged from nozzles. Due to this, among conventional inkjet printers, there are ones having an inkjet head provided with a heater for heating ink for a purpose of reducing the viscosity of the ink, so that the ink can appropriately be discharged from the nozzles.
However, in the conventional inkjet printer that heats the ink by the heater in the inkjet head, since the ink that has already been present inside the inkjet head and heated by the heater is cooled by the ink supplied from the outside of the inkjet head at a portion where the ink is supplied from the outside to the inside within the inkjet head and in a vicinity thereof, unevenness in temperature is generated in the ink inside the inkjet head depending on locations. The unevenness in temperature being generated in the ink inside the inkjet head depending on the locations means that unevenness in viscosity is generated in the ink inside the inkjet head depending on the locations. When the unevenness in viscosity is generated in the ink inside the inkjet head depending on the locations, an ink droplet discharging accuracy is varied for each of the nozzles of the inkjet head by the unevenness in viscosity of the ink inside the inkjet head. Accordingly, in the conventional inkjet printer that heats the ink by the heater in the inkjet head, there is a problem that an image quality of printing is degraded.